The present invention relates to a reel feed screen printing method and printing machine. More particularly, it relates to a reel feed screen printing method and printing machine capable of avoiding contact of the printed portion of the film positioned at the drying oven side with the drying oven inlet or the like.
Hitherto, as a method of printing an image on a substrate, for example, a printed wiring board, screen printing is known, which is to print on the object of printing rubbing out ink from a stencil screen by means of a squeegee.
FIG. 8 shows a structure of a conventional reel feed screen printing machine. This printing machine 100 reels out a PET film Fxe2x80x2 coated with a ceramic thin film from a reel feed roller 101 by a specified length each, prints on the ceramic thin film by means of a stencil screen 102, dries the printed portion by a drying oven 103, and takes up by a reel-up roller 104.
Such reel feed printing method is superior in working efficiency and effective to lower the manufacturing cost, as compared with the method of printing on each one of preliminarily cut sheets.
Hitherto, if precise print position is required as in the case of overlap printing of an image on an already printed image, at the time of first printing, a positioning mark is printed together with the print pattern, and this mark is taken by, for example, a CCD camera, and the position of the object of printing is adjusted on the basis of the taken image information.
However, in the positioning method by using image pickup means such as CCD camera, the CCD camera is placed between the object of printing and the screen, and the distance of the object of printing and the screen is wider than usual. Therefore, when bringing the object of printing and the screen closer to each other at the time of printing, the camera must be set aside, and the object of printing or the screen must be moved a relatively long distance, but since the screen requires a considerably wide area than the printing area of the object of printing, when the screen is moved, the camera withdrawing distance is very long, and one process becomes long.
Accordingly, a method of printing by fixing the screen and bringing the object of printing closer to the screen is advantageous in working efficiency, but in this case, in the printing machine 100 in FIG. 8, the PET film Fxe2x80x2 is lifted about the printing area, and the printed portion may contact with the inlet of the drying oven 103, and the machine may be contaminated or the printing result may be poor.
The invention is devised in the light of the above problems of the prior art, and it is hence an object thereof to present a reel feed screen printing method and printing machine capable of avoiding contact of the printed portion of the film positioned at the drying oven side with the drying oven inlet or the like.
A first aspect of reel feed screen printing method of the invention is a reel feed screen printing method for performing screen printing while feeding a roll film by a specific stroke, in which the drying oven side of the film is slackened at the time of printing.
A second aspect of reel feed screen printing method of the invention is a reel feed screen printing method for performing screen printing while feeding a roll film by a specific stroke, in which the print table is lifted up to a printing position while moving in the drying oven direction by a specific stroke.
In the reel feed screen printing method of the invention, preferably, the drying oven side of the film is thrust downward.
A first aspect of reel feed screen printing machine of the invention is a reel feed screen printing machine for performing screen printing while feeding a roll film by a specific stroke comprising film slackening means for slackening the drying oven side of the film at the time of printing.
A second aspect of reel feed screen printing machine of the invention is a reel feed screen printing machine for performing screen printing while feeding a roll film by a specific stroke comprising print table sliding and lifting means for lifting the print table up to a printing position while moving in the drying oven direction by a specific stroke.
The reel feed screen printing machine of the invention, preferably, further comprises film downward thrusting means for thrusting the drying oven side of the film downward.
The invention is thus constituted, and hence the printed portion positioned at the drying oven side of the film at the time of printing is prevented from being damaged by contacting with, for example, the upper part of the inlet of the drying oven. Accordingly, the product quality and yield are enhanced, and soiling of the drying oven inlet with ink or the like can be avoided.